Dual chamber diaphragm resonator and sound device -



Jan. 25, 1955 H. GORDON ET AL 2,700,316

DUAL CHAMBER DIAPHRAGM RESONATOR AND SOUND DEVICE Filed Oct. 20, 1953 "lai s .1W

v f j? i l i a( 1 a i *fa/Y N .2/5 'j l INVENTORS BY WW/V5 imm? l www Y United States Patent O DUAL CHAMBER DIAPHRAGM RESONATOR AND SOUND DEVICE Harry Gordon and Irving Fiske, New York, N. Y. Application October 20, 1953, Serial No. 387,116 2 Claims. (Cl. 84-330) This invention relates to sound producing devices or resonators, and the main object is the provision of a dual chamber diaphragm resonator and sound device having certain novel and useful improvements enhancing the utility and range of the device.

Another object of the invention is the provision of a device of the class above referred to, including a iiexible stretchable diaphragm which is caused to vibrate during the operation of the device, with novel and practical means for simultaneously varying the tension applied to the diaphragm and the effective musical length of the air column beneath it thus varying the pitch as well as other properties of the emitted sound.

The above broad as well as additional and more specifc objects will be clarified in the following description wherein characters of reference refer to like-numbered parts in the accompanying drawing. It is to be noted that the drawing is intended solely for the purpose of illustration and that it is therefore neither desired nor intended to limit the invention necessarily to any or all of the exact details of construction or operation illustrated or described except insofar as they may be deemed essential to the invention.

Referring briey to the drawing, Fig. l is a perspective view of the sound producing device constructed on the principles of the present invention, with parts broken away and partly in section.

Fig. 2 is an exploded perspective view of the device, with parts broken away and partly in section.

Fig. 3 is a sectional view of the assembled device illustrating its operation, taken on the line 3-3 of Fig. 2.

Referring in detail to the drawing, the numeral indicates a cylindrical cup having a ange 11 extending outwardly from its rim and further having a substantially horizontal inlet nipple or mouthpiece 12 providing an air passage into the cup near the bottom thereof. A ilexible and stretchable circular diaphragm 13, formed of any suitable material such as, by way of example, rubber, and provided with a circumferential bead or lip 14, is secured as a seal over the open top of the cup by engagement of the lip 14 under the llange 11, as illustrated in Fig. 3, the diaphragm being stretched or tensed in the operation of thus assembling it.

A threaded axial passage 15 is provided through the bottom of the cup 10, and a pipe 16, of greater axial length than the cup and having screw threads 17 extending for a relatively short distance along the outside thereof between the ends or intermediate the length of the pipe, extends through the opening 15 into the cup with the threads 17 in engagement with the threaded opening 15. The upper portion 16a of the pipe 16, that is, the length of the p ipe which lies between the threads 17 and its upper extremity,

is approximately equal to the depth of the cup. Hence, the upper end of the pipe 16 always lies in a plane not distant from and parallel with the plane through the rim of the cup. Simultaneously the effective musical length of the air column beneath the diaphragm is increased or decreased accordingly.

As a consequence of the threaded engagement of the pipe in the cup, as above described, it is obviously possible to vary the degree of tension on the diaphragm by varying the vertical position of the pipe with respect to the cup, and the latter operation is accomplished merely by screwing the pipe upward or downward with respect to the bottom of the cup.

The arrows in Fig. 3 indicate the direction taken by air blown through the inlet 12 into the device, which air exits by raising the diaphragm above the upper rim of the pipe, thus, as is well known, producing vibrations or sound. Obviously, the greater the tension applied to the diaphragm is, the higher will be the pitch of the emitted sound. As a consequence of the axially movable relationship between the pipe and the cup, as above set forth, it is readily possible for the operator to play a tune by effecting proper and properly timed axial movement of the pipe with respect to the cup while he blows into the mouthpiece. As with all musical instruments, practice with the instant device will improve ones ability in playing tunes.

Obviously, modications in form or structure will or can be made without departing from the spirit or scope of the invention as defined in the appended claims.

We claim:

1. A device of the class described comprising a cup open at the top and having an axial opening through the bottom, said cup having an inlet through the wall thereof adapted to have air blown therethrough into the cup, a pipe having the same external diameter as the diameter of said axial opening being axially movably mounted in said axial opening and positioned coaxial with the cup, the upper end of said pipe being normally positioned in the plane through the rim of the cup, and a diaphragm of ilexible stretchable material, said diaphragm being mounted stretched across and sealing the open top of the cup, the central portion of said diaphragm also being stretched across and sealing the upper end of said pipe, said diaphragm upon blowing air through said inlet being raised above said top of said pipe thereby initiating vibration of the diaphragm which continues during the said blowing, said vibrating diaphragm emitting sounds, the tension of the diaphragm and the musical length of the air column under the diaphragm being varied upon varying the axial position of the pipe with respect to the cup with consequent variation of the tone emitted by the device.

2. The device set forth in claim 1, said cup having screw threads surrounding said axial opening, said pipe having external screw threads engaging said first-named threads whence said axial movement of the pipe with respect to the cup is achieved by rotation of the pipe with respect to the cup.

References Cited in the file of this patent UNITED STATES PATENTS 

